Response of MoS2 nanosheet field effect transistor under different gas environments and its long wavelength photoresponse characteristics

A convenient method is utilized to fabricate MoS2 nanosheet field effect transistor (NSFET) instead of current expensive and fussy photo-etching or electron-beam lithography technology. The electrical characteristics of MoS2 NSFET under air and NH3 environments are studied both by experiment measurements and theoretical calculations. The experimental results illustrate that the performance of NSFET is distinctly altered under NH3 environment, and our first-principles calculations show it is the adsorbed NH3 molecules that transfer electrons to the MoS2 nanosheet, changing its resistivity. This phenomenon suggests that MoS2 could be used as gas sensors. Red light response of the NSFET at 633 nm wavelength is also achieved, which can improve the use of MoS2 as photodetectors. (C) 2014 Elsevier B.V. All rights reserved.